Alkaline earth metal base greases and their preparation



y 17, 1956 J. B. STUCKER ETAL 2,755,248

ALKALINE EARTH METAL. BASE GREASES AND THEIR PREPARATION Filed oct'. 16,1951 GREASE KETTLE t E E g I: Q '44 l N 0% Q G) 0: 1): 52 Ek 3 mINVENTORS JOSEPH B. STUCKER BY ERNEST TI FRONCZAK AH'ORN United StatesPatent 2,755,248 ALKALINE EARTH MET L BASE GREASES AND THEIR PREPARATIONJoseph B. Stucker, Des Plaines, and Ernest T. Fronczak, Crystal Lake,111., assignors to The Pure Oil Company, Chicago, Ill., a corporation ofOhio Application October 16, 1951, Serial No. 251,482 4 Claims. (Cl.252-40 characteristics of greases which bear importance as far asmanufacture and use are concerned, comprise consistency, consistencystability, melting or flow point, yield value, the free acid or alkalicontent, and stability in storage and use. Numerous techniques have beendeveloped for both batch and continuous methods of grease preparation.However, these techniques provide for little flexibility in the greasecomposition for a given type of grease and are built around expensivelow viscosity index lubricating oil fractions. Also, prior methods areapplicable to those' types of grease wherein the attainment of a stablegel structure presents little difliculty as, for example, alu-. minum orlithium soap greases. It is generally considered that it is morediflicult to attain good texture, high yield values, and stability inthe manufacture of soda soap, soda-lime soap, and lime-base greases thanother types of grease. Those processes directed to the preparation oflime-base greases require tedious processing techniques, employingexpensive lubricating oil stocks, and often depend upon expensiveadditives, as high molecular weight synthetic polymers, to attain thedesired results. Automotive chassis greases have been prepared usingGulf Coast type lubricating oils which are entirely satisfactoryperformance-wise, but the cost of manufacture is high and the processingtechnique often tedious. In addition no flexibility of the compositionis attained whereby chassis greases can be prepared for use in divergentclimatic conditions requiring stringent viscosity/ temperaturerelationships in the grease using prior methods of manufacture.

Another difiiculty with existing grease manufacture processes andcompositions is that they are not amendable to the use of solventrefined lubricating oils unless low viscosity neutral fractions areused, and even then the required soft, fine grain texture andcompatibility with metal soaps is lacking. Solvent refined oils have notgenerally been. used in the manufacture of greases, especially lime-basegreases because of the incompatibility of the oil with the lime soapsand the fact that the viscosity of the solvent refined oils cannot bevaried within the broad limits necessary to form greases operable underextremes of climatic conditions. If it is attempted to raise theviscosity index of the solvent refined oils by employing blends ofsolvent refined neutral stocks and high viscosity index solvent refinedbright stocks, the result is a destruction of the gel structure of thegrease.

2,755,248 Patented July 17, 1956 The primary object of this invention isto provide a method of manufacturing greases and compositions thereforewhich overcome these difficulties. It has been found that greasecompositions may be prepared using solvent refined lubricating oilstocks by including in the formulation substantial portions of solventextract from the solvent refining of lubricating oils. Greasesformulated in accordance with this invention using the techniques hereindescribed and the compositions disclosed not only eliminate theforegoing difiiculties but also meet the most exacting specifications.Greases formulated in accordance with this invention do not needexpensive additives or expensive highly refined lubricating oil bases asa part of the composition in order to meet the required viscosity/temperature relationships for various climatic conditions, the tackinessand water-insolubility required of a chassis lubricant, or theflexibility required for economic production. The diagram is asimplified representation of the apparatus employed and theflow ofingredients in conducting the present process.

One of the objects of this invention is to provide grease compositionscontaining alkaline earth metal and alkali metal soaps, or alkalineearth metal soaps wherein the mineral lubricating oil base is flexibleas concerns its physical characteristics.

An object of this invention is to provide a grease composition in whichthe mineral lubricating oil base comprises the less expensive solventrefined lubricating oils in combination with the solvent extract fromlubricating oil fractions.

Another object of this invention is to provide a limebase greasecomposition in which the viscosity of the mineral lubricating oil basecan be varied from about 150 SUS at F. to about 5000 SUS at 100 F.

A further object of this invention is to provide a limebase chassisgrease composition which exhibits desired properties of pumpability,tackiness, adhesiveness, and consistency stability.

Another object of this invention is to provide a limebase greasecomposition which includes a high viscosity index mineral lubricatingoil base and, therefore, displays improved viscosity/ temperaturecharacteristics.

Another object of this invention is to provide a method for compoundinggrease compositions using solvent refined mineral lubricating oilstocks.

The present invention contemplates a grease which has a small moisturecontent for use at temperatures up to F., under medium pressures andmedium speeds and which contains a substantial amount of a solventextract from a mineral lubricating oil and a small amount of limesodasoaps. The solvent extracts used in accordance with this invention areobtained during the manufacture of neutral and bright lubricating oilstocks.

In a typical operation, desalted crude oil is first charged to adistillation unit where straight run gasoline, two grades of naphtha,kerosene, and virgin distillate are taken oft", leaving a reduced cruderesidue. The reduced crude is continuously charged to a vacuumdistillation unit where three lubricating oil distillates are taken offas side streams, a light distillate is taken off as overhead, and aresiduum is withdrawn from the bottom of the tower. This residuum ischarged to a propane deasphalting unit wherein propane dissolves thedesirable lubricating oil constituents and leaves the asphalticmaterials. A typical vacuum residuum charge to the propane deasphaltingunit may have an API gravity of 12.9, viscosity SUS at 210 F. of 1249,flash 585 F.', fire 650 F., C. R. of 13.9 weight per cent and is blackin color. The deasphalted oil may have an API gravity of 21.5 to 21.8,viscosity SUS at 210 F. of -175, NPA color 6-7, flash 575 F., fire 640F., and C. R. of,1.72.0.

The deasphalted oil and various lubricating oil distillates from thereduced crude are separately subjected to solvent extraction for theseparation of non-aromatic from aromatic constituents. The refined oilor raflinate from such processes is used as blending stocks and thesolvent extract, containing the undesirable aromatic constituents, isthe material found useful in accordance with this invention. 7

For example, a Van Zandt crude oil with an API Percent by weight Fattyacids 8-9 Hydrated lime 1.5-1.7 Caustic .0l0.20 Solvent extract 60-65Mineral oil 24-30 Water 02-35 A specific example of a grease compositioncompounded in accordance with this invention comprises:

gravity of 33.1 was topped to remove such light fractions 10 asgasoline, naphtha, kerosene, and a light lubricating Percent y Wcighldistillate. The vacuum residue was a reduced crude hav- Animal fattyacids 8.40 ing a viscosity of 1251 SUS at 210 F., 2.2 per cent sul-Hydrated lime 1.60 fur, and an API gravity of 12.6. After propane (18-Sodium hydroxide 0.06 asphalting, the oil had a viscosity of 174 SUS at210 F. Phenol extract from bright stock mfr 62.77 and an API gravity of21.7. This dcasphalted oil was Neutral lubricating oil 26.89 treatedwith phenol to produce a raffinate from which Water 0.28 an aviationlubricating oil may be produced. The extract phase from this phenoltreatment is ready for use FT of 3 f formula Shows the followmg inpreparing greases in accordance with this invention. 0 0 mac ens mes anes Other solvents than phenol may be used to obtain the Soda soappercent 0.8 extraction product used in accordance with this inven- Limesoap do 9.0 tion; for example, furfural or the Duo-Sol solution com-Mineral oil do 89.0 prising liquid propane, phenol, and cresol may beused. Free acid do .00 When using phenol, it is possible to vary thecharacter- Free alkali do .03 istics of the extraction productconsiderably by adjust- Unworked consistency (A. S. T. M.) 294 ment ofthe amount of water present. A low V. I. cut Worked consistency (A. S.T. M.) 290 may be obtained by using a water solution of phenol Apparentviscosity in poises at 77 F. with rates during the extraction and a highV. I. cut may be obof shear (seetained by using anhydrous phenol.Following are the 10 720 physical characteristics of typical extractionproducts 100 162 from bright stock from Van Zandt crude oil which may1,000 53 be used in accordance with this invention. 10,000 28Consistency stability Good TABLE I Physical characteristics of phenolextracts Extract API Viscosity/ Viscosity] Vlscoslty/ V. I. Pour,Percent Percent No. Gravity 100 F. 130 F. 210 F. F. R. Sulfur s. s 145,000 ,00c 616 0 The extracts shown in Table I are merely illustrative andthe invention is not to be limited thereby. It is to be understood thatany solvent extract from the refining of lubricating oils for thepurpose of separating nonaromatic and aromatic hydrocarbons will applyand be useful in the present invention, provided it can be blended witha lubricating oil to form the proper viscosity blend for greasemanufacture.

By using solvent extracts in substantial quantity in greasecompositions, the processing technique is simplified and the resultingproducts display the desired viscosity/temperature relationships, passthe commercial requirements of consistency stability, display therequired characteristics of pumpability, tackiness, and require lessmetal soap in the composition to give a good grease consistency.Furthermore, greases prepared in accordance with this invention areadhesive to metal parts, waterinsoluble, and provide excellentlubrication at temperatures up to 150 F. or as low as 30 F.

The following formula sets forth the general limits of the ingredientsof the new grease. This formula is not to be considered as restrictive,since the proportions may be varied so long as the characteristics andproperties of the compositions are not departed from in any substantialmanner. Grease compositions prepared in accordance with this inventionmay be of any consistency from 0 (worked penetration 355-385) to 5(worked penetration 130-160). I

The mineral oil used was a blend of Mid-Continent solvent refinedneutral and heavy stock having a viscosity of about 2400 SUS at F., V.I. 45, and an API gravity of 20.5. If the viscosity of the mineral oilis increased to as much as 3000 or 4000 SUS at 100 F., the apparentviscosity of the finished grease at high shear rates (10,000 SCCI'I) canbe increased appreciably above the 28 poises shown above. The fattyacids referred to include both animal and vegetable fatty acids, asstearic acid, palmitic acid, etc. The above grease qualifies as No. 2consistency summer chassis grease, is readily pumped through standardgrease pumping equipment and forced through the various fittings of anautomobile chassis. It will adhere to the bearing surfaces attemperatures up to F. and is not affected by water. In testing thisgrease, it was found that the apparent viscosity at high shear rates isdependent on the mineral oil viscosity and soap content of the greasewhile the apparent viscosity at low shear rates is dependent on theyield, that is, the per cent by weight of soap needed to form a greaseof a certain consistency.

In general, the process of formulating greases in accordance with thepresent invention comprises heating and agitating the solvent extract ina mixing chamber; preparing a slurry of aportion of the lubricating oiland lime; preparing a solution of caustic soda, adding the caustic sodasolution to the phenol extract at a temperature of about F. whilecontinuing the agitating and heating thereof; bringing the solventextract to about 180 F. and then slowly adding a portion of the limeslurry; continuing the heating and allowing the mixture to reach amaximum temperature of 203 F.; holding the mixture at this temperaturefor a period of time while adding the balance of lubricating oil, whichis followed by the addition of the fatty acids; and finally theremaining portion of the lime slurry is added.

After checking the free alkalinity and making corrections to bring thefree alkali in the range of 0.01 to 0.10 per cent, the agitation iscontinued for about 15 minutes. The samples are drawn and quick chilledto determine the worked penetration. with lubricating oil stock and thebalance of phenol extract until a particular quick-chilled penetrationis achieved. The grease is then ready for drawing and packaging.

Referring to the diagram, lubricating oil stock is introduced tolime-slurry mixer 1 by means of line 2. Mixer 1 is fitted with stirrer 3and valve 4 controlling the flow of slurry to pump 5. Pump 5 isconnected to dispersion and recirculating system 6, comprising eductor7, by-pass 8, disperser 9, and recycle line 10. Line 11 serves as atake-01f for completed slurry conveying it to reaction kettle 12, fittedwith stirrer 13 and caustic inlet 14.

Following the diagram, 21 detailed description of the process of thepresent invention is presented based on a 10,000 pound batch of grease(10,168 pounds total). The components for this example composition are:

TABLE II Component Pounds Animal fatty acids r. 855 Hydrated lime r 163Caustic soda r 7 Phenol extract i r r r 6, 380 Viscosity 200 SUS at 100F., MOSR Neutra 2, 735 Water .1 28,,

The kettle 12 was first charged with 6,380 pounds of phenol extract(about 750 gallons at 60 F.) and agitation through stirrer 13 and heatare applied. About 500 pounds of 200 vis neutral oil were added to theslurry mixer tank. About 163- pounds of lime were added through theeductor 7. Agitation of the slurry mixer tank was begun by means ofstirrer 3 and valve 4 opened to start the dispersion and recirculatingsystem 6. The valves and by-pass 8 were then adjusted to gradually pullthe lime into the system, through the disperser 9 and through recycleline 10 into tank 1. Seven pounds of caustic soda were dissolved in 28pounds of water and the solution added through line 14 to kettle 12 whenthe phenol extract therein had reached a temperature of about 160 F.Agitation and heating were continued. When the extract reached 180 F.,about 80 pounds of lime/oil slurry from dispersion system 6 were addedthrough line 11. Heating and agitation in kettle 12 were continued,allowing the mixture to reach a maximum temperature of about 203 F.

The mixture was maintained at a temperature of 200 F. to 203 F. forabout 15 minutes, during which time about 1,735 pounds of 200 visneutral lubricating oil were added. 855 pounds of animal fatty acidswere then added to the mixture in kettle 12, and the temperatureadjusted to 200 F. to 203 F. The remainder of the lime/ oil slurry intank 1 was next added to the contents of kettle 12. Immediatelyfollowing this step, it is well to wash the slurry mixer tank with 500pounds of 200 vis neutral, preferably in two stages so that hang-up oflime within the system'is minimized.

The mixture in kettle 12 was agitated at 200 F. to 203 F. for about 30minutes after the last wash oil had been added from'the previous step.At this stage in the process, it is convenient to check the freealkalinity :which should be maintained within the range of 0.01 "to Thenthe mixture is cut back 0.10 per cent. If acid or lime are necessary tocorrect the alkalinity, the agitation is continued for 15 minutes toinsure complete reaction. If no correction is necessary, the agitationis continued for one hour after the addition of the wash oil.

The progress of the grease formation should be determined by withdrawinga sample, quick-chilling, and determining the 60-stroke workedpenetration. The sample should have a worked penetration of about 290 atthis point. The entire batch was next cut back with 200 vis neutral lubeoil and phenol extract to a quick-chill penetration of about 320 to 340.The grease is ready for packaging. The total time elapsed in the batchprocess is about three to three and one-half hours.

In order to further demonstrate the invention, a series of experimentalgrease batches were prepared using different mineral lubricating oilbases and different types of fat stock. Some batches were prepared usingthe ordinary cut-back method of pressure saponification of the fat stockfollowed by dehydration of the lime soap, cut back with mineral oil,hydration of the grease and reduction to consistency in the normalfashion. Other batches were prepared using a modified method wherein aportion of the mineral oil base and all the fatty acids are mixed andheated to 180 to F., then the sodium hydroxide added as a 25 per centaqueous solution. Thebalance of the mineral oil base was used to preparea lime slurry (approximately one part by weight of lime and three partsof neutral oil). This lime slurry was added to the batch and thetemperature raised to 200 F. The temperature was maintained at about 205to 210 F. for about two hours and the remainder of water added. Solventextract was then added over a period of about two hours and thetemperature allowed to drop to to 200 F., at which temperature thegrease was drawn.

Still another method was employed, designated special in the table,wherein the procedure was to charge a portion of the neutral oil, allthe fatty acids, and all the phenol extract to the grease kettle and themixture was heated to about 160 F. or enough to melt the fatty acids.The caustic soda (as a 25 per cent solution) was added and thetemperature slowly raised to about 230 F., agitation was continued andthe temperature allowed to drop to about 205 F. Next, the lime slurry ofneutral oil and lime heated to 200 to 205 F. was added and additionalhot neutral oil used to flush out any remaining lime slurry from thelime slurry mixer. The kettle was maintained at about 200 to 210 F. fora period of one and onehalf to two hours without exceeding 210 F. afterthe lime slurry was added. The batches were drawn at 190 to 200 F. Thismethod is exemplified by batch number 13. Lastly, Table III shows batch15 was prepared using the preferred method which has heretofore beendescribed. These modifications in procedure were a matter of alteringthe ordinary cut-back method to obtain a process whereby a good greasehaving the desired characteristics could be prepared, using highviscosity solvent extracts with solvent refined oils, most economicallyand efiiciently without the chance of failure to form a good grease.

From Table III it is apparent from batch numbers 1 and 5 that Gulf Coastoils may be readily used to compound lime-base greases using fatty acidsor yellow grease (containing glycerides). Neutral stocks, bright stocks,or phenol extract alone, or phenol extract from the preparation ofneutral stocks are difficult to handle in grease making and do not yielda product having the proper characteristics, as good grease structurewithout the presence of grain. This is shown by batches 2, 3, 4, 5, and6. From phenol extract from the manufacture of bright stock (batch 7)formed a grainy grease and was difficult to hydrate. The addition ofbright stock to a neutral stock (batch 8) completely disintegrated thegel structure. However, the combination of phenol extracts and neutrallubricating oil stocks of various yiscosities TABLE III PercentConsistency Weight Percent and Type Manuiac- Soap Free Acid or No. ofMineral Oil turing Type of Fat To Ob- Alkali Remarks Procedure tam 1111-Worked Grease worked 1 .1 100% 2,046 Viscosity/100 F. Cut-back Fattyacids.. 9.1 328 328 0.03% Acid.-. Good yield, good consistency and GulfCoast Oil. grease structure, meets desired apparent viscosity of 35-40poises at 77 F. with 10,000 Seeshear rate, slight aeration. 100%Viscosity 200 SUS at Modified" "hide 15. 0.06% Alkali--. Poor yield.lumpy. hang-up on stir- 100" F. Neutral. ring paddles, grainy structure.100% 150 Intermediate V.I. .do do 26.0 Very soft grease gel structurealmost Bright Stock. gone, low yiel 100% Viscosity 200 SUS at Cut-back-Yellow grease 26.0 0.08%A1kali Difficult to hydrate, soft grainy 100 F.Neutral. grease, low yield. 100% 2,000 Viscosity/100 F. do do 10.5 323Good yield, good grease structure, Gulf Coast Oil. meets desiredapparent viscosity characteristics. 6 100% Phenol Extract from (ln -(ln15.0 Pooryield,very soft grease.

Feutral Stock Manufacure. 7 100% PhenolExtract #2 (in (lo 25.0 Diflicultto hydrate, grainy structure, low yield. 8 33% Viscosity 200 SUS at -doFatty acids 15.6 386 376 0.17% Alkali-.- Grease structure entirelydisinte- 100 F. Neutral, 67% 150 grated. Viscosity 97 V. I. Brt. Stk.9.- 65% Phenol Extract #1, 35% do Yellow grease 15.0 226 242 0.15%Acid.-Good grease structure, easy to by 200 Vis. Neut. drate, no grains. 10.65% Phenol Extract #3, 35% Modified Fatty acids 15. 0 0.20% Acld.. Fairgrease structure, slight aeration.

isositty 200 SUS at 100' on 11. 65% Phenol Extract #3, 35% do do 13. 0302 295 0.03% Acid Good grease structure, good yield.

isosity 200 SUS at 100 cu 12 65% Phenol Extract #3, 35% do do 11. 0 339316 0.07% Add... Very good grease structure, excellent gislc ositty 200SUS at 100 yield.

eu 13-- 65% Phenol Extract #4,35% Special do 9.5 306 311 0.09% A0ld.Good grease structure, good yield, Viscosity 160/180 SUS at no grains,consistency after 5,000 100 F. N cut. strokes 339 (84 F.). 14"..- 65%Phenol Extract #3, 35% Modifieddo 11.0 308 311 0.05%Alkali..- greasestructure, consistency Viscosity 160/180 SUS at after working 500strokes 314; 1,000 100 F. Neut. strokes 326; 5,000 strokes 326 (Temp. 90F.), apparent viscosity at 1;: 1 and a 10,000 Sar -30.0 p0 s. 15 70%Phenol Extract #3, Preierred -do 9.8 294 290 0.03% Alkali.-. Good greasestructure and consist- Visoosity 200 SUS at 100 ency stability, nofoaming, no F. Neut. grains.

proved to be the most satisfactory for both yellow grease and fattyacids, as evidenced by batches 9 to 14.

In preparing these grease compositions, it was observed that there was atendency for the finished grease to be slightly acid. This is notdeleterious and the degree of acidity or alkalinity can be adjustedduring the final stages of preparation by extracting a sample,determining the per cent of acid or alkali and adding a small amount ofalkali or acid to make the proper adjustment. It is generally preferredthat the greases be slightly on the alkaline side, although this is notmandatory. The tendcncy of the grease compositions to be slightly acidmay be accounted for by the presence of naphthcnic acids in the solventextracts used.

The yellow grease used in the above compositions has a saponificationnumber of 192, an iodine value of 58, and showed on analysisconsiderable glyceridc content along with about 12 per cent by weight offree fatty acids, calculated as oleic acid. The hydrated lime assayed atabout 91 per cent calcium hydroxide. The fatty acids have asaponification number of from 200 to 208, iodine value of to 57, and thefatty acid content ranges from 95.5 per cent to 100 per cent, calculatedas oleic acid. The titer value C. ranges from 40 to 41 Greasecompositions have thus been described containing lime soaps and smallamounts of soda-soaps. Calcium soaps may be incorporated as the alkalineearth metal soap with or without small amounts of alkali metal soaps,such as sodium, potassium, or cesium soaps. Lime base greases containingonly limo-soaps may be prepared by the methods of this invention. Asabove stated, the fatty acids may be of animal, vegetable, or syntheticorigin, and generally mixtures of saturated and unsaturated organicfatty acids having 10 or more carbon atoms to the moleculearcconternplatcd. Those fatty acids are contemplated for use in thisinvention which form soaps yielding a gel structure which is stable andfree from grainincss. The proportions of each of the ingredients may bevaried within the limits disclosed without departing from the spirit ofthe invention. Likewise, the amount of dilution or cut-back in the finalstages of preparation to attain the desired consistency may be variedwithin limits known to the art.

It has thus far been demonstrated that by employing the techniques ofthe present invention, there will be produced stable greases havingconsistencies, apparent viscosities, and consistency stabilities whichare generally desired for greases useful as winter chassis lubricants,summer chassis lubricants, cup greases, or hot mill or roll neckgreases. Using the techniques herein disclosed, a soft grain grease isattainable, containing no lumps and the procedure is devoid of suchprocessing difiicultics as foaming and local overheating.

It is generally desirable that chassis greases, especially those to beused under different climatic conditions, exhibit certain prescribedpressure/viscosity characteristics for a designated consistency range.For example, a Number 1 consistency grease, which is known as a summerchassis grease, should have a worked penetration of 310 to 340, andshould display the following pressure/viscosity characteristics:

Shear Rate Sec. 4

Viscosity (poiscs) at 77 F.

amas

desired pressure/viscosity characteristics for winterchassis greases,cup greases, journal box greases, hot mill and roll neck greases can bealso attained. Greases prepared using the described techniques do notbecome soft on being worked, nor do their gel structures disintegrateduring use. The greases are easily pumped through chassis fittings andgreasing equipment under divergent climatic conditions.

It has also been found that, by incorporating a certain combination ofextreme pressure additives into greases prepared in accordance with thisinvention, a product is obtained having the extreme pressurecharacteristics necessary for heavy duty industrial uses. A greasemeeting the Timken Roller Bearing Companys specifications for use onheavy duty steel mill roller bearing equipment may be prepared usinglead naphthenate in combination with an additive marketed under thetrade name of Stan-Add 48, which is a sulfurized terpene productdeactivated at temperatures of about 200 to 250 F. to render itnoncorrosive at 200 F. The sulfurized terpene is described in and may bemade in accordance with United States Patent 2,445,983. Such greasemeets the Timken Roller Bearing Company specifications for heavy dutyuse, including freedom from foreign constituents, fillers, etc., therequired consistencies, noncorrosiveness to copper or steel at normalbearing temperatures, and the required extreme pressure qualities. Thislatter characteristic is demonstrated by the prevention of scoring onthe Timken lubricant tester, using a minimum load of 33 pounds on thelever arm at a minimum rubbing speed of 400 feet per minute.

A series of experiments were conducted to demonstrate that greasecompositions made in accordance with this invention may be furtherblended with a certain combination of extreme pressure additives to passthe Timken test. The results of these experiments are shown in thefollowing Table IV.

TABLE IV Beam Test Grease No. Composition Load, Rating Pounds AnimalFatty Acids Seizure. Hydrated Lime Do. 15 Sodium Hydroxide. 0. PhenolExtract Lubricating Oil W .2

. Do. Do. D0.

. D0. Tricresyl Phosphate. Grease #15 Do. Tricresyl Phosphate ChassisGrease A Do. {Chassis Grease A. D0.

Tricresyl Phosphat 1. Chassis Grease A Do. Dibenzyl Disulfide- 4.Chassis Grease A Do. Additive B 1. 0 Chassis Grease A 97.0 25 D0. 3.0 33Do. a o 79.0 33 Pass. 10.0 33 Seizure.

" Sulfur 1. 0 10.0

15 94. 0 33 Pass. 26 Stan-Add 48 1.0 33 D0.

Lead N aphthenate 5. 0 Grease #15 94. 5 27 Lead Naphthenate 5. 0 33 Do.Stan-Add 4 0.5 33 D0. Grease #15. 92. 62 33 Seizure. 28 LeadNaphthenate. 5.0 33 D0. Additive O 2. 38 33 Do.

Referring to Table IV, the preferred grease composition #15 withoutextreme pressure additives will not pass the Timken test. Greases 16through 19 show that dibenzyl disulfide or tricresyl phosphate alone arenot adequate to meet the test when incorporated in the preferred grease#15. Chassis grease A, a lubricant manufactured by ordinary methods,does not pass the test with or without additives, as shown by greases.20, 21, 22, and 23. The combination of lead naphthenate, air-blownasphalt and sulfur or lead naphthenateand' additive C also failed tocarry grease #15 through. the Timken test as shown by greases number 25and 28. Greases 26 and 27, the latter being-the preferred formulationsince the degree of sulfur activity was optimum, represent acombinationwhich passes the Timkene'xtreme pressure test.

In preparing these extreme pressure greases, the extreme pressureadditives may be incorporated into a finished lime-base greasecomposition in amounts sufiicient to attain the desired characteristicsor may be incorporated during the steps of preparation. The preferredprocedure comprises adding the lead naphthenate and sulfurized terpeneafter the step of adjusting the free alkalinity, while the grease is at-160 F. with continued agitation. After the elapse of about one hourfrom the time of addition of the wash-oil, the agitation is stopped andthe product cut to desired consistency.

Although the invention has been described by disclosure of specificembodiments exemplifying the preferred method of preparation and thepreferred compositions, the only limitations to be placed upon the scopeof the invention appear in the appended claims.

What is claimed is:

1. A lubricating grease comprising the following ingredients in weightper cent:

C15 to C13 animal fatty acids 8-9' Hydrated lime 1.5-1.7 Caustic soda0.01-0.20 Phenol extract from bright stock manufacture,

API gravity 8.6 to 15.4", viscosity at 100 F. of 15,000 to 145,000 SUS60-65 Solvent refined neutral lubricating oil 24-30 Water 0.2-0.35

2. A lubricating grease in accordance with claim 1 in which the fattyacid is selected from the group consisting of stearic acid and palmiticacid and mixtures thereof.

3. A lubricating grease comprising the following ingredients in weightper cent:

4. The method of preparing a lime-base grease comprising heating andagitating about 6,300 parts of phenol extract having an API gravityabout 8.6 and a viscosity at 100 F. of about 36,410 SUS obtained fromthe manufacture of lubricating oil bright stock in a reaction kettle toabout to F., said extract containing a predominance of aromatichydrocarbons, preparing a limeoil slurry of about 500 parts of solventrefined neutral lubricating oil having a viscosity of 200 SUS at 100 F.and about 160 parts of hydrated lime by thorough mixing and dispersion,adding about 28 parts of water containing about 7 parts of sodiumhydroxide to the phenol extract, slowly adding about 80 parts of thelime-oil slurry to the phenol extract and sodium hydroxide mixture,heating and agitating the mixture until a maximum temperature of 203 F.is reached, adding about 1,700 parts of said solvent refined neutrallubricating oil and 855 parts of animal fatty acids having 16 to 18carbon atoms per molecule while maintaining the temperature at 200 to203 F., adding the remaining portion of lime-oil slurry to the mixture,correcting the free alkalinity to within 0.01 to 0.10 percent,

References Cited in the file of this patent UNITED STATES PATENTS McKeeMar. 1, 1927 12 Finlay Jan. 22, 1929 Taylor et a1. Apr. 28, 1936 Kaufmanet a1. Oct. 20, 1936 Gothard et a1 June 17, 1941 Morway et a1. Mar. 2,1943 Zimmer et a1 Aug. 10, 1943 Brunstrum et al. Apr. 9, 1946

1. A LUBRICATING GREASE COMPRISING THE FOLLOWING INGREDIENTS IN WEIGHTPER CENT: PHENOL EXTRACT FROM BRIGHT STOCK MANUFACTURE, API GRAVITY 8.6*TO 15.4*, VISCOSITY AT 100*